Feature: An entity World2d is defined with a coordinate system (x,y)

    As a world creator
    I want to create a World in 2 dimensions with a (x, y) coordinate system

    Scenario: world2d definition with a (x, y) coordinate system
        Given nothing
        When I create World2d from Entity with 2 Axis x and y
        Then World2d should have an Axis called x and an Axis called y
        And the class World2d_x_Metric should exists
        And the class World2d_y_Metric should exists
        And World2d_x_Metric should extend Metric
        And World2d_y_Metric should extend Metric

